Electrical apparatus



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Patented July 1o, 192s.y

UNITI-:Dl STATES 1,676,921 AP .LVIENT oaFlcE.

, LOUIS A. M. PHELAN AND CLIFFORD HOTCHKISS,` OF BELOIT, WISCONSIN, ASSIGNOIRS,

BY DIRECT AND MESNE ASSIGNMENTS,

A CORPORATION OF INDIANA.

ELEcTRfcAL APPARATUS.'

TO ABSOLUTE CON-TAC-TOR CORPORATION,

Hussain f Application led December 23, 1922. Serial No. 668,703.

Our invention relates to electrical switches designed particularly for the regula-tion or control of electrical circuits, such as may be 'used in connection with heating, cooling or alarm apparatus and systems.

The subject matter of this invention has reference to a device making use of a liquid electrical contactor tube, which comprises a container in which are mounted spaced elec-` trodes adapted to be bridged by a body of mercury when the container is properly actuated.

Our invention makes use of an electrical contacter of the above mentioned type, mounted in'conjunction with heat or pressure responsive devices, such as curved pressure tubes and thermostatic elements. The pressure responslve or thermostatic element is designed to support and serve to actuate the electrical contactor into or out of circuit closing position when a pressure or temperature change of a predetermined amount occurs.

More particularly our device refers to an.

electric switch of this type in which the pressure or thermost-atic element is unusually eflicient, accurate and rapid in operation.

A further particular object of our invention is to providev a ready means for adjusting the above type of device to operate at required predetermined conditions.

Another object of our invention is to produce a contactor tube of the above character, which may be readily mounted upon an actuating device which has available a very small quantity of energy for actuating the contactortube and which will require only a small change in pressure or temperature for its actuation.

A further object of our invention is to provide a switch device offthe type indicated, that will be simple and economical to construct and which will possess great durability, even whenl subjected to mechanical abuse and when used in connection with c nsiderable quantities of electric curren at substantial voltages. Y

Also further objects and advantages will appear from the following specification and Fig. 3 is a. detail sectional View taken on lin 3 3 of Fig. 2; l.

1g. 4 shows a modification having a special type of casing;

Fg. 5 shows a modification having still another type of casing or housing;

. Fig. o(iis a detail sectional view similar to Fig.. 3 but showing a modified form of ther- \mostatic element and contactor tube;l

Fig. 7 is a front. view of the device o Fig. 6; and, f

Figs. 8 and 9 are detail sectional views of vfurther modilications.

In a general way our invention, as shown ,f

in Fig-1, comprises the liquid contactor tube l mounted upon a conical spiral thermostatic bi-metallic element 2, which in turn is pivotally mounted at 3 to the frame or support 4. A cover-5 serves to protect land enclose the device.

The tubefl is constructed in a substantially toroidal form, preferably in the form offa torus. After the various parts in the tube are in place, the tube is evacuated and filled with an inert gas and sealed off throughthe tip 6. Electrodes 7 and 8 are inserted and sealed in the walls of the tube and may be formed of platinum or of-Dumet wire covthe like metal which is unaffected by the arcing obtaining in the tube in the presence of the mercury and the mercury vapor. A body of conducting fiuid 9, preferably mercury, may substantially fill the lower half of the container l and is normally in con.`

tube is tilted into or out ofcircuit making' position. In other words, the body of conduct-ing fiuid 9, aswell as the tube l, retain ,a substantially stationary center of gravlty when the tube is actuated. Hence it is ob-v vious that -`ve little energy is required either to initial y move the tube or to return the tube to its normal posltion, since the 'ered'or plated with casings of pure iron or r `parts remain practically balanced at ally y spaced points.

lthe glass tube.

times. In the formertypes of liquid contacter tubes, it has been necessary to displace a fairly large mass of heavy liquid in order to actuate the device. Such contactors have the further disadvantage that an appreciable teniperature change is required to restore the parts including the body of conducting liquid to their normal position after once actuated.

The tube lis mounted concentric with the outer turn 2a of spiral element 2 by means` of detachable clips 10 comprising flexible bands of copper or similar material soldered or otherwise fixed to the spiral turn 2L and clasped around the tube 1 at opposite and structure forms a very simple, compact and easily assembled arrangement of the, contacter tube and the thermostatic element.

The spiral element 2 is preferably constructed of a bi-metallic ribbon composed of layers of any suitable metals or alloys, such as brass and nickel, and is wound substantially in the vshape f a conical or helical spiral as shown. This form of winding -has a particular advantage over the more usual simple spiral form in that a much larger portion of the surface area ot the thermostatic ribbon or heat responsive element is directly exposed to the atmosphere dand air currents. This is an important consideration when this type of device is used for accurate and rapid temperature regulation. This form of conical spiral mounting has a further advantage in the present structure, in that it makes possible a moreconvenient arrangement of the lead wires to the contactor tube and permits the contacter tube to be flexibly mount- 'ed at a centra-l position in the casing remote from any of the lixed parts of the structure which would possibly hit against and break The inner end of the spiral element 2 is mounted upon a pivotingshaft'S which is retained in a frame 4 by a nut 3 and washgI 3b. A collar 11 sugrounds the pivotingi 'screw 3 and is fixed to the spiral element 2 by solder or by means of a screw 12. i The collar 11 is provided with an extension 13 which forms a handle for adjusting the angular position of the tube 1 and the spiral element 2 about its pivoting shaft 3. Thehandle 13- extends to the exterior of the casing and is provided'with a pointer 14 co-operating with 'acalibratedA scale 15 formed on an extension of the frame 4.

The electrodes 7 and 8 are connected in the circuit, respectively, bythe flexible leadl wires 16 and 17. The flexible wire 16 is at-l tached to the outer end of the s iral element '2 so that'the electric current flowing in the' circuit will traverse this element for the particular purpose/hereinafter described. From f the spiral element' 2 the y circuit continues through .frame 4 to a binding post 19. The,

It will be noted that this flexible lead 17 is connected tor a binding post 20.` The binding posts 19 and 20 serve to connect the device to the desired external circuit.

The cover 5 is attached to the frame 4 by means oi? lugs 2l formed integral with the lower end of the frame 4 and by a lug` 22 formed at the upper end of the frame 4 and engaged by a screw 23. Openings 24 are provided in the cover 5 fort e purpose of permitting l'ree circulation o air currents about the thermostatic element 2. The cover 5 is provided with a thermometer 25 which serves as a guide 'when adjusting the switch to actuatc at a desired ten'iperature.

Screw holes 26 may be provided in the frame 4 for mounting the device upon a wall or partition surface.

ln Fig. 4, the device is shown mounted in a modified form oli' casing. The casing here consists of a body portion 27 and a cap por-f tion 28 having a flange 29., which is intended to be mounted flush with a wall surface.

ln Fig. 5, the device is shown mounted in another modified form of casing, comprising a rear enclosing frame 30, a mounting plate 31, and a cover portion 32. The rear frame 3() constitutes a weather-proof connection box for the electrical leads and is provided with a threaded opening 35 for a conduit connection.

In Figs. 6 and 7, a modified structure is shown in which a cylindrical contactor, tube 3G is used. The tube 36 isl designed to be normally located in a position neinhboring the horizontal and upon beingtilte a body of mercury 37 is designedto flow into and out of bridging relation with a pair of electrodes 38 and 39 which are connected in circuit in 'the manner of electrodes 7 and 8 above described. A4 contacter tubeof this type has been found to Vbe accuratelyl remore readily the cylindrical type of con` tactor tube. tache'd by means of rivets 42 to a supporting arm 43. y

In Fig. 8, a -further modification is shown in which 'a hollowr spiral thermostatic ele- :me'nt 44 isl used. The hollow portion of this spiral element may-form a continuous passage throughout the length of the spiral and may be'connected at t end', if desired, with a container` 45. The passage through the spiral element and the container 45 may be filled with air or other fluids, which'when heated will result in a change in pressure. This pressure change will serve to valter The spiral element 40 is at-l the shape ofthe spiral element 44 and thus actuate the contacto'r tube. It will be understood that container 45 is merely disclosed as an example of a source of pressure changes and that the contacter tube and spiral element shown in Fig. 8 are capable ofI use with, and may be actuated by, other desired sources of varying pressure.

In Fig. 9, a modification is shown embodying features shown in Figs. 3 and-8. A hollow spiral element 46 is shown having outer and inner walls 46a and 46" composed respectively of materials having d'fferent coelicients of expansion. This spiral element may also be attached to a source of variable pressure. such as the Huid container 47 and hence this element is subject to van alteration in shape when temperature changes occur. both because-of its bi-metallic nature angl because of its act'on asa curved pressure tu e.

In all of the above described structures it will be noted that the use ot' bearings in the operating parts of the mountings of lthe contacter tubes is entirely eliminated. Consequently the spiral elements when actuat.

ing the contacter tubes, are not required to overcome any-variable frictional losses as would result with the use of bearings.

The operation and one method /ofnusing the deviceof F ig. 1`will now be outlined. The binding posts 19 and 20 are connected directly in series-with the circuit which is to becontrolled such, for example, as the circuit of a motor controlled heating equipment of any ,of the usual and suitable types. Assuming that the room temperature is at or near the desired point, the lever 13 is turned so that the 'contactor tube 1t is in a substantially neutral position ready to either close or'open the circuit with a very slight change of temperature. If it is assumed that the device is being used for the regulation ot heating equipments and that the room is at the desired temperature, then the heating apparatus should not be in full operation and consequently the contactor tube should be in open circuit position. with the body of mercury 9 out of contact w`th` the electrode 7. vHowever, as the room'tem perature drops a predetermined amount. the thermostatic element 2 will become modified in shape because of the temperature change and Will rotate the contactor tube l about its axis into circuit closing position.

The current to the contactor tube will now How through the spiral element 2 and Will start th'e'operation of the heating equipment. The spiral element 2 will thereupon begin to return to its normal position and will begin to rotatel the contactor. tube back to its former position as a result of two causes: first. the heating equipment will have partially restored the room temperature and second, the current running through the element.- With such a apparatus.

of the heating apparatus and to. the time required to bring the room temperature and the temperature of the thermostatic element back to normal. This will result in a room temperature considerably in excess of that desired before the thermostatic element is su'liciently heated to cause the heating equipment to be shut off. Hence, in order to use this typey of regulating switch where the temperature must be regulated-very accurately, it is advisable to supplement the action of the increased room temperature upon the spiral element 2 with theheating action ot' the current flowing, through this found possible to regulate the room temperature withv an accuracy several degrees closer than with the former methods;l

However, in case thistype of thermostatic switch is used in connection with the control of refrigeration or cooling apparatus, it will ordinarily beI cohn'ected -in circuit and adjusted to open the circuit upon the occurrence of a suliicientidrop in temperature. This is the opposite oi its action when used with heating apparatus where it serves to device it has been open the circuit uponthe occurrence of a y suiiicient increase in temperature. In View of these facts, the heating effect of the current through the spiral element is unnecessary in the case of refrigeration and cooling Consequently in the device as shown in Fig. 4, the current is net connected through the spiral element but independent lead wires 16a and 17a are provided to the binding, posts.` In other instances it may be desirable' to pass onlyy a portion ofthe total cui-'rent through the spiral element and in such cases ashunt Wire 16", as shown in Fig. 5, may be so designed vto by-pass the desired amount of current.

The terms contactor,iliquid contactor and electrical contactor as employed in the claims contained herein refer to the'well known type of mercury electric switch or an equivalent thereof which comprises an'herr metically sealed container having electrodes disposed therein and a body of conducting v i' liquid, such zas mercury, which serves to `make and break the electric circuit between the said electrodes. The' various modifications of our invention shown iny the ldrawings are illustrative of several types of such contactors as are coveredby our present iny movable by the coiled thermostatic element and which is adapted to control an electric circuit by cooperating with a second yand fixed open contact member.

lVhile we have shown and described several embodiments of our invention, it is to be understood that many modifications may be made therein without departing from the spirit and scope of' the appended claims, and we desire that only such limitations shall be imposed upon our invention as are specifically pointed out in the claims and such as are required by the prior art. I

Having thus described our invention, what we claim as new and desire to secure by Letters Patent in the United States, is:

l. A thermostatic switch comprising a coiled thermostatic element, a liquid contactor wholly\ supported on and movable with said element, a body of' conducting liquid housed in said contacter, and an adjustable supporting means for said element for adjusting the position of said contact-or.

2. A thermostatic` switch comprising fit' heat responsive element formed of' conducting` material, a liquid contacter comprising a container, cooperating electrodes sealed therein and a conducting body housed in said container, said contactor being Wholly supported upon one end of said element, and an electrical circuit to .-said conta/ttor connected'through said element to one of said electrodes. A

3. A thermostatic switch comprising a heat responsive element formed ofl conducting material, a liquid contactor comprising a container, cooperating electrodes sealed therein and a conducting body housed in said container, said eontactor being wholly supported upon a free end of`said element, and an electrical circuit to said contactor connected through said element to one of said electrodes, whereby the/ current that may flow in said circuit :serves to heat and thereby tends to actuate said element.

'4. A thermostatic switch comprising a thermostatic element, and an electrical liquid contactor, including co-operating electrodes of opposite polarity, said element being fixed atV one end and free at its other end and said electrical liquid ,contactor being wholly supported upon said free end.

5. A thermostatic switch mprising a coiled thermostatic element an an electrical liquid coutactor including co-operating elec.-

of said element and said contactor. Y

6. An electrlcal switch comprising a spi- .coiled tlierniostat'ic element, a liquid con- 'justment ofthe actuating position of said rally shaped tube filled ,with a fluid, and an electrical contactor, saidtube being fixed at one end and free at its other end and said contactor being entirely mounted upon-said free end. 4 7. Av thermostatic switch comprising a coiled thermostatic element, a liquidl contactor mounted on the inner end thereof, and supporting means fixed to the outer end of said element, said supporting means being in turn pivotally mounted in order to provide for adjustment ofthe angular position of the said liquid contactor.

8.- A thermostatic switch. comprising. a

tactor mounted on the inner end thereof, and adjustable supporting means having in turn a mounting pivoted substantially coaxially with said coiled element in order to provide for adjustment of the angular position OV said liquid contactor.

v9. A thermostatie switch comprising a heat responsive element, a liquid contactor operable upon being tilted and wholly supported on the free end thereof, and supporting means fixed -to the other end of said element, said supporting. means being pivotally mounted in order to provide for adliquid contactor.

l0. A thermostatically operated electric switch comprising a thermostatic element, a mounting to which one end only of said element is fixed, a tiltable contractor mounted and wholly supported upon the other end of i said element, said contactor comprising :a container, electrodes therein and a conducting body movable therebetween, and means for adjusting the tilting angle of said contactor.

ll. A thermostatic switch comprising a heat responsive element in the form of'a substantially conical spiral, the end of said element at the base of the conical spiral being fixed, and an electrical contactor wholly and tiltably supported upon the end of said element at the apex of the conical spiral.

12. -A thermostatic electric switch comprising a coiled .thermostatic element having only one of its. ends fixed, a liquid contacter operable on being tilted and supported wholly upon the other end of said thermostatic element, and means for` adjusting the angular position of' said liquid contactor thereby.- permitting said thermostatic element y to tilt said contgctor at predeterm-ined temperatures.

13. A' thermostaticpgswitch. comprising a coiledf'thermostatic element having only one 1 of its'ends fixed, a liquid contactor operable onv being tilted wholly carried ,by and.

mounted upon the free end of said thermostatic element, and means for 'adjusting the angular positionof said liquid contactor to permit nsaid thermostatic element to operlilo ate it at diierent predetermined temperatures..

14. An electrical device comprising a coiled thermostatic element, a mounting member, a bracket mounted on said mounting member and having one end only of said thermostatic element secured thereto, a liquid contactor operable on being tilted and mounted uponand carried by the free end of said thermostatic element, said bracket being adjustable for varying the angular position of said liquid contactor thereby permitting said thermostatic element to operate said liquid contactor at predetermined ltemperatures. l 15. An electrical device comprising a spirally coiled thermostatic element, 'a mounting member, a bracket adjustably pivoted upon said mounting member, the outer end of said thermostatic element being secured to said bracket, and a liquid lcontactor mounted upon and carried by the inner end of saidV thermostatic element at its axis.

16. An electrical device comprising a coiled thermostatic element, a mounting member, a bracket pivoted upon said mounting member, one end of said coiled `thermostatic element being secured to said bracket, and a liquid contactor mounted.

upon land carried by the f ree end of said thermostatic elemen 17. An electrical device comprising a coiled actuating element, a mounting member, a bracket adjustably secured to said mounting member, one end of said element being secured tol said bracket, and a vliquid ,j contactor wholly supported upon and carried by the free end of said element.

18. A thermostatic switch comprising a ltliermostatic coil, a mounting member, a

bracket pivotally secured to said mounting member, the outer end of said coil being 4attached to said bracket, and a liquid` cony tactor wholly 'supported upon the free end of said coil. i i

19. An electrical device f comprising a thermostatic spirally coiled element, a

mounting member, a bracket pivoted thereto,

the outer end of said .element being attached to said bracket, and a liquid contactor dissed at the axis thereof, said contactor ing wholly supported upon the `free end of, said element. i

20. A thermostatic switch comprising a coiled actuating element, a'liquid contadtor operable upon beingtiltedand mounted upon the free end of said coiled element adjacent to the axis thereof, and supporting means to which the other end of said coiled element is attached, said supporting means being adjustable-to provide for adjustment of the tilting angle of said contactor.

2l. An electrical device comprising a,

`thermostatic coil, a liquid contactor operable upon being tilted and mounted adjacent to the axis thereof and wholly'supported upon' the free end of said coil, supporting means to which the other end of said coil is secured, said supporting means being adjustable ,in order to provide for varying the actuating position of said contactor,Av and electrical connections for said contactor constituting said coil as a part thereof.

22. An electric switch comprising an actuating element having only one end thereof iixed, a tiltable liquid contactor being mounted and wholly supported upon the free end of said element, said contactor comprising a container, electrodes therein and a conducting bod movable therebetween, and means for a justing said actuating element whereby the tilting angle of said contactor for opening and closing its associated electric circuit may be varied.

23. An' electric switch comprlsing a heat responsive actuating element having only one end thereof fixed, a tiltable contactor mounted and wholly supported upon the free end of said element, said contactor comprising a container, electrodes therein and a conducting body movable therebetween, said heat responsive element serving to tilt said scribed our names.

LOUIS A. M. PHELAN. CLIFFORD HOTCHKISS. 

